Change axes.prop_cycle to single line in mplrc

Otherwise the example is invalid because the matplotlibrc parser
doesn't understand multi-line commands. See matplotlib#9184.

matplotlibrc.template

@@ -330,14 +330,9 @@ backend      : $TEMPLATE_BACKEND
 #axes.unicode_minus  : True    # use unicode for the minus symbol
                                # rather than hyphen.  See
                                # http://en.wikipedia.org/wiki/Plus_and_minus_signs#Character_codes
-#axes.prop_cycle    : cycler('color',
-#                            ['1f77b4', 'ff7f0e', '2ca02c', 'd62728',
-#                              '9467bd', '8c564b', 'e377c2', '7f7f7f',
-#                              'bcbd22', '17becf'])
-                                            # color cycle for plot lines
-                                            # as list of string colorspecs:
-                                            # single letter, long name, or
-                                            # web-style hex
+# axes.prop_cycle    : cycler('color', ['1f77b4', 'ff7f0e', '2ca02c', 'd62728', '9467bd', '8c564b', 'e377c2', '7f7f7f', 'bcbd22', '17becf'])
+                      # color cycle for plot lines  as list of string
+                      # colorspecs: single letter, long name, or web-style hex
 #axes.autolimit_mode : data # How to scale axes limits to the data.
                             # Use "data" to use data limits, plus some margin
                             # Use "round_number" move to the nearest "round" number